Synergistic insecticidal compositions



States SYNERGISTIC INSECTICIDAL COMPOSITIONS Howard A. Jones and John A. Garman, Baltimore, Md., and Berton C. Dickinson, Lyndonville, N.Y., assignors to Food Machinery and Chemical Corporation, New York, N.Y., a corporation of Delaware No Drawing. Original application Mar. 24, 1955, Ser. No. 496,596. Divided and this application Oct. 17, 1958, Ser. No. 767,7 84

'4 Claims. (Cl. 167-22) combinations are highly effective and economical to use for such large-scale insecticidal requirements as the control of truck crop, forage crop and orchard insects.

The synergistic compositions of this invention can be formulated as aqueous emulsions, as dry or Wettable powders, as solutions or in any other suitable vehicle. The insecticidal compositions can be utilized as sprays, as dusts, as aerosol mixtures, insecticidal coating compositions, and as residues. In general, they can be applied by methods commonly used for control or eradication of insects, mites and the like. Thus these insecticidal compositions can be formulated with solvents, diluents and carrier media, adhesives, spreading, Wetting and emulsifying agents and other ingredients. V

The relative proportions of the active ingredients as well as inert carriers, solvents, dispersants and the like It is, in fact, quite probable that it differs with difierent The term synergism can be countered in combinations of two or more biologically active components in which the combined activity of the two components exceeds the sum of the activities of the components when used alone. The insecticidal activity of the mixed components cannot be predicted from known values of the individual components, but is unpredictable and depends on the individual activity of neither.

It is an object of this invention to provide insecticidal compositions of enhanced killing power. Another object of this invention is to produce novel compositions containing compounds capable of synergizing the knockdown and killing properties of individual toxicants. A further object of this invention is to provide compositions including a relatively toxic phosphorus containing insecticide in which superior insecticidal activity is obtained because of the synergistic eifects, but in which the ultimate toxicity to warm-blooded animals is greatly reduced because of the lower concentrations of the phosphorous compounds required when used in combination with the relatively less toxic carbamates. Other objects and advantages of the invention will become apparent from the description of the invention set forth below.

According to this invention there are provided synergistic insecticidal compositions comprising QO-dimethyl S-(1,2 dicarbethoxyethyl) dithiophosphate, hereinafter called Malathion, and an organic carbamate ester of the following general formula wherein R is ethyl and R is selected from the group consisting of 4-nitrophenyl, 4-methylphenyl and 4-phenylphenyl radicals. These carbamates may be prepared as described in copending application Serial No. 812,113, filed May 11, 1959.

The synergistic insecticidal compositions of this invention may be used on a wide variety of insects and mite species, but are particularly effective against such insects as the two-spotted spider mite and squash bug. The

i for dispensing the dust.

may vary within Wide. limits.v

Thus the relative proportion (ratio) of the Malathion to the carbamate ester can range from 20 parts of the former per 1 part of the latter to 1 part of the former per 40 parts of the latter and preferably about 1 part of the former to about 2 parts of the latter.

The quantities of the component toxicants in the final insecticidal compositions can range from 0.01% to 25.00% for the Malathion and from 0.05% to 50.00% for the 'carbamate, and preferably from 0.10% to 10.00% for the Malathion and from 0.10% to 25.00% for the carbamate.

1 The procedures of the testing methods are described below. The details of the test experiments including the type of formulation and mode of application or dosing, and the species of insects which served as test subjects are given in the examples.

squash bug (Anasa trz'stis).

The test methods used are described as follows:

DUST TOWER METHOD This general method is described in the following reference, Moore, J. Econ. But. 43, N0. 2, 188-190 (1950). The dusting apparatus consists of a vertical glass cylinder, 34 inches high and 8.5 inches in diameter, into which the appropriate dust sample is discharged through a small hole in the center of the cover, by means of a small-laboratory duster operating at an air pressure of 40 p.s.i.g. The duster assemblycomprises a 10 ml. beaker, into which the Weighed sample is placed, and fitted with a rubber stopper through which pass the air inlet and dust outlet tubes, both of which are made of 4 inch diameter copper tubing. At the outer end of the air inlet tube is a trigger valve that serves as a control The inner end of this tube reaches nearly to the bottom of the beaker. The end of it. is sealed but, along the sides, seven 0.032 inch holes are drilled at irregular intervals which serve as airinlets. Such an arangement causes pronounced turbulence of the dust and thus insures exhausting the complete sample from the beaker. The dust. outlet tube forms. an arch from the top of the beaker to the top of the glass dusting tower.

After discharge of the sample into the tower, there is allowed a 2-minute settling time before removal of foliage or insects being treated. A weighed metal plate is placed in the tower each time a test is made, and by weighing the amount of dust deposited on it, it is then possible to calculate the amount applied per acre.

Because of day-to-day variations in the results obtained by this test method, comparisons among the in;

dividuarcomponents and their combinations were made simultaneously in order tominimize this source of" variation.

Slight modifications in this test employed for specific insect species are as' noted below;

Tw'o spottgidbpidr hzita-Ih tests o n' two spotted mites; the mites-= were-confined' to. the upper surfaces of potted bean plants by a"tangl'efoot ring. The bean plants were placed in the-glass towerand the 'rnitesdirect-dusted.- Mortalityreadings=were'- taken in' 24hours.- Only adult miteswereused in determiningmortality counts;

Squash bug.----]?"or this test squashdeaves were collected in the field and the cut ends of the stemwere wrapped in moist cotton. Individual leaves were then-placed' in 35inchPetrhdishes-and dusted as described above. Each treated leaf was then infested with last instar squash bug nymphs and the coversof the Petri dishes were'replaced. At the end of 24 hours the'treatedleaves were removed" and fresh untreated leaves'were introduced into the dishes. Mortality counts were taken after the bugs hadrbeenonthe untreated leaves for 24 hours.

4 dimethyl S-(1,2-dicarbethoxyethyl) dithiophosphate and an organic carbamate of the formula Table 1;

N 000K H Carbamate Phosphate I I Rate" (Lbs; Test Method Test Subject; Mortality Dust Dust /A.) (Percent) R R" Cone. Name Cone:

(Percent) 7 (Percent) Ethyl 4-Chl0rophenyl 1 0 50. 8 ;DustTower SquashBug 0 I 46.1 do 0 Ethyl #Ghlorophenyl 1:0 5 51.2 1 d0 d0'. 100 1 Do.-- a-Methylphenyl 0.5 11.2 do 'Tvlrg-tspotted Spider 0 -3-Methylphenyl; 0.5 10.4- 99 fi-Dlmethylph'en 0.5 K 10'. 5 4 1 12.6 66 3,5-Dimethylphenyl. 0.5 11.2 100 '-Methoxyphenyl 0. 5 12. 8 0

13.7 34' 4-Methoxyphenyl 0V5 11.5v 98 4-Phenylphenyl O. 5 33. 2 .0 .1 28:3. 0- -Phenylphenyl 0. 5 32. 4 80- The: results of the data summarized in Table 1 demon.- strate the marked synergism-10f the insecticidal compositions of. this inventionon a number" of insects.

This application is a division of copending application Serial No 496,596 =filed tMarch 124, 195 5; now abandoned, which is a continuation-in-part of Serial No. 4275374, filed May 3', .1954; now abandoned.

Weclaim:

1. .Synergistieinsecticidal compositions comprising 0 0. dimethyl S-(1,2l-dicarbethoxyethyl) dithiophosphate and. 4-methoxyphenyl; N-ethylcarbamate; said components being; present in the: ratio 1 of about 2 parts of said car-- bamate CStlztO about l 'partiof said dithiophosphate';

' 2i Syuergistiminsecticidal.compositions 'comprising 0,0: dimethyl; S-(lgfidicarbethoxyethyl) dithiophospliate and. 4'-pl'ienylpl1eny1Niethylearhamate; said'icomponentsbeing presentaini the; ratio:- of: about 2. parts ofi said? carbamate" sistingof 4 methoxyph'enyl and 4-phenylphenylradicals;

and wherein saidcornponents are present in the ratio of about two partsof saidcarbamate perpart of said'di thiophosphate.

References Cited'in the file ofthis patent UNITED STATES PATENTS 2503390., Jelinelc Apr. 11', 1950 Gysin': ;May 25,- 1954: 

3. SYNERGISTIC INSECTICIDAL COMPOSITIONS COMPRISING O,ODIMETHYL S-(1,2-DICARBETHOXYETHYL) DITHIOPHOPHATE AND AN ORGANIC CARBAMATE OF THE FORMULA 